| abstract |
In the case of a vacuum cleaner for industry and household, in which the speed control of the vacuum cleaner blower motor is carried out by evaluating the dust concentration in the suction line that results in each case by means of optoelectric devices (10) (light transmitter, light receiver), it is proposed that the signal pulses originating from the light receivers depending on the dust particles detected to control another light transmitter (light-emitting diode) (11a, 11b), to which a light-sensitive resistor (24) is directly assigned, which is also part of the control resistor (26) of a triac (28) located in the motor circuit of the blower motor (29). The optoelectric dust concentration measuring arrangement can preferably have a plurality of light transmitters and light receivers and can be arranged directly in the air inlet opening of a vacuum cleaner housing. |